Lateral Approach to the Femur‌

The lateral approach is the incision used most often for gaining access to the upper third of the femur. It also can be extended inferiorly to expose virtually the whole length of the bone. Although it is an extremely quick and easy approach, it involves splitting the vastus lateralis muscle. The subsequent blood loss that results from the rupture of vessels during this procedure may make surgery awkward, but rarely is life-threatening. The posterolateral approach to the femur does not involve muscle splitting and for this reason is favored by some surgeons for surgery on the proximal femur.

The uses of the lateral approach include the following:

1. Open reduction and internal fixation of intertrochanteric fractures (this is by far the most common use of the approach)

2. Insertion of internal fixation in the treatment of subcapital fractures or slipped upper femoral epiphysis

3. Subtrochanteric or intertrochanteric osteotomy

4. Open reduction and internal fixation of femoral shaft fractures, subtrochanteric fractures, and supracondylar fractures of the femur

5. Extra-articular arthrodesis of the hip joint

6. Treatment of chronic osteomyelitis of the femur

7. Biopsy and treatment of bone tumors

 

Position of the Patient

 

Patients with trochanteric fractures should be placed on an orthopedic table in the supine position so that their fractures can be manipulated or controlled during surgery. Use an orthopedic table for any procedure that involves the use of an image intensifier (Fig. 9-1). Internally rotate the leg 15 degrees to overcome the natural anteversion of the femoral neck and to bring the lateral surface of the bone into a true lateral position. For most extracapsular hip fractures internal rotation helps fracture reduction. Having the femoral neck parallel to the floor is helpful in positioning the femoral neck guidewire correctly.

For surgery on the shaft of the femur a lateral position can also be used. Place the patient on his or her side, with the affected limb uppermost. Take care to pad the bony prominences of the bottom limb to avoid pressure necrosis of the skin. Place other pillows between the two limbs to pad the medial surface of the knee and the medial malleolus of the side that is being operated on.

Landmarks and Incision Landmarks

The posterior edge of the greater trochanter is relatively uncovered.

Palpate it, moving the fingers anteriorly and proximally to identify its tip.

The shaft of the femur is palpable as a line of resistance on the lateral side of the thigh.

Incision

Make a longitudinal incision, beginning over the middle of the greater trochanter and extending down the lateral side of the thigh over the lateral

aspect of the femur. The length and position of the incision will vary with the requirements of the surgery (Fig. 9-2).

Radiographic control of the length and position of the incision significantly reduces the length of the incision. Because it is accurately sited, this in turn reduces the amount of dissection and soft tissue damage necessary for adequate exposure.

 

Figure 9-1 Position of the patient on the operating table for the lateral approach to the proximal femur.

 

Internervous Plane

 

There is no internervous or intermuscular plane, because the dissection splits the vastus lateralis muscle, which is supplied by the femoral nerve. The muscle receives its nerve supply high in the thigh, however, so splitting the muscle distally does not denervate it.

 

Superficial Surgical Dissection

 

Incise the fascia lata of the thigh in line with the skin incision. At the upper end of the wound, the distal portion of the tensor fasciae latae may have to be split in line with its fibers to expose the vastus lateralis (Fig. 9-3). This split is needed in about one-third of patients, those who have tensor fasciae latae fibers extending distally beyond the greater trochanter.

 

Figure 9-2 Incision for the lateral approach to the proximal femur.

 

Figure 9-3 Incise the fascia lata in line with the skin incision.

 

Deep Surgical Dissection

 

Carefully incise the fascial covering of the vastus lateralis muscle (Fig. 9-4). Insert a Hohmann or Bennett retractor through the muscle, running the tip of the retractor over the anterior aspect of the femoral shaft. Then, insert a second retractor through the same gap and down to the femoral shaft. Manipulate the second retractor so that it moves underneath the femur, and pull the two retractors apart to split the vastus lateralis in the

line of its fibers (Fig. 9-5).

Continue splitting by blunt dissection. As dissection proceeds, several vessels that cross the field will be exposed. Coagulate them, if possible, before they are avulsed by the blunt dissection. Avoid sharp dissection straight down to the bone. Numerous vessels will be cut and because they retract into the muscle they are often difficult to coagulate or ligate.

Splitting the vastus lateralis reveals the underlying lateral surface of the femur.

 

Figure 9-4 Incise the fascia covering the vastus lateralis.

 

Figure 9-5 Split the fibers of the vastus lateralis. To develop a subperiosteal plane, squeeze two Hohmann retractors down to the femoral shaft and separate them to split the vastus lateralis further.

 

Dang

 

Vessels

Numerous perforating branches of the profunda femoris artery traverse the vastus lateralis muscle (see Fig. 9-48). They are damaged during the approach and should be ligated or coagulated. These arterial branches can be identified more easily if the muscle is split gently with a blunt instrument rather than cut straight through with a knife.

 

How to Enlarge the Approach

Extensile Measures

The approach is most useful for exposing the proximal third of the bone for internal fixation of a hip fracture. It can be extended to the knee joint, however, to allow full exposure of the lateral aspect of the femoral shaft for reduction and fixation of all types of femoral fractures (Fig. 9-6; see

Fig. 9-51).

 

Figure 9-6 The incision may be extended distally to expose the entire shaft of the femur.